kernel-ark/fs/nfs/delegation.h
Trond Myklebust e6f8107595 NFS: Add an asynchronous delegreturn operation for use in nfs_clear_inode
Otherwise, there is a potential deadlock if the last dput() from an NFSv4
close() or other asynchronous operation leads to nfs_clear_inode calling
the synchronous delegreturn.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-30 02:06:12 -05:00

75 lines
2.2 KiB
C

/*
* linux/fs/nfs/delegation.h
*
* Copyright (c) Trond Myklebust
*
* Definitions pertaining to NFS delegated files
*/
#ifndef FS_NFS_DELEGATION_H
#define FS_NFS_DELEGATION_H
#if defined(CONFIG_NFS_V4)
/*
* NFSv4 delegation
*/
struct nfs_delegation {
struct list_head super_list;
struct rpc_cred *cred;
struct inode *inode;
nfs4_stateid stateid;
int type;
#define NFS_DELEGATION_NEED_RECLAIM 1
long flags;
loff_t maxsize;
__u64 change_attr;
struct rcu_head rcu;
};
int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res);
void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res);
int nfs_inode_return_delegation(struct inode *inode);
int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid);
void nfs_inode_return_delegation_noreclaim(struct inode *inode);
struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs_fh *fhandle);
void nfs_return_all_delegations(struct super_block *sb);
void nfs_expire_all_delegations(struct nfs_client *clp);
void nfs_handle_cb_pathdown(struct nfs_client *clp);
void nfs_delegation_mark_reclaim(struct nfs_client *clp);
void nfs_delegation_reap_unclaimed(struct nfs_client *clp);
/* NFSv4 delegation-related procedures */
int nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid, int issync);
int nfs4_open_delegation_recall(struct nfs_open_context *ctx, struct nfs4_state *state, const nfs4_stateid *stateid);
int nfs4_lock_delegation_recall(struct nfs4_state *state, struct file_lock *fl);
int nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode);
static inline int nfs_have_delegation(struct inode *inode, int flags)
{
struct nfs_delegation *delegation;
int ret = 0;
flags &= FMODE_READ|FMODE_WRITE;
rcu_read_lock();
delegation = rcu_dereference(NFS_I(inode)->delegation);
if (delegation != NULL && (delegation->type & flags) == flags)
ret = 1;
rcu_read_unlock();
return ret;
}
#else
static inline int nfs_have_delegation(struct inode *inode, int flags)
{
return 0;
}
static inline int nfs_inode_return_delegation(struct inode *inode)
{
return 0;
}
#endif
#endif